简介:Theanalysisofstableisotopesofcarbonandoxygenindifferentcarbonaterocksbythephosphoricacidmethodisnoteasierthanthatbythelasersamplingmethoddevelopedinrecentyears,whichopticallyfocuseslaserbeamswithsufficientenergyonamicroareaofathinsectioninavacuumsampleboxviamicroscope.CO2producedbyheatingdecompositionofcarbonatewaspurifiedbythevacuumsystem,andthestableisotopicvaluesofcarbonandoxygenwerecalculatedandanalyzedonamassspectrometer.Thispaperadoptedthelasermicro-samplingtechniquetoanalyzethestableisotopesofcarbonandoxygenindolomite,carbonatecement,stromatoliteanddifferentformsofdawsonite(donbassite).Resultsindicatedthatthelasermicro-samplingmethodiseffectiveinanalyzingcarbonatecompositionandcouldbeaconvincingproofforjustificationoncarbonatecompositionanalysis.
简介:Basedondetailedgeologicstudy,theimportantroleofstructuringintheformationofgolddepositsintheareaisdiscussedwithspecialreferencetostructuralevolution,Syngeneticfaultingcontemporaneouswithtectonic-volcaniceventsisthoughttoberesponsibleforprovidingtheore-formingmaterialatdepth.ThelithofaciesformedbyhighlyalternatingdepositionofterrestrialandcarbonatedetritusischemicallycharacterizedbytheassemblageofAu-Sb-As,constituteingafavorablesourcebedfortheactivationandenrichmentofgold.Thisgoldsourcebedhasundergonefourmajorstagesofstructuraldeformation,accompaniedbymulti-stagedalterationandmineralization.